8.2 is higher than it should be, although this in itself may not prove diabetes. It's very important for him to be tested though, I would book him a doctors appointment in the near future.
It depends on what the conditions were when you did the test. If it was just an "on spec" test, you know, jab him while he's quiet, then up to 11 is allowed.
Hi, as ' the squire' says it depends on what time of day and when they've been eating.
If your grandson is a child and you are worried about T1, these are the signs to look for (actually no different for T1 in an adult)